The rapid gains in digital technology and telecommunications have increased the desirability of having a network in the home to interconnect a multitude of products in the home with each other and to the outside world. The range of available outside services includes interactive services, cable video and audio services, satellite networks, telephone company services, video on demand, and other types of information services. However, penetration of the personal computer into homes in the, United States is approximately 33% and only growing slowly, although governments desire more extensive penetration to encourage "telecommuting" and reduce road traffic and pollution. Further penetration of computers in the home will originate from the purchase of consumer entertainment and informational products containing an embedded computer and operating system hidden by an opaque user interface. Such a product is a conventional set-top box.
Set-top boxes are multi-media computers that augment the use of televisions. A conventional set-top box has an external network interface module that connects the set-top box to the external network and data provider. The network interface module has to perform a number of sophisticated functions, such as interfacing to a specific external network, tuning, demodulation, error correcting, video descrambling, recovery of MPEG clock, and encryption and decryption specific to the external network. Consequently, the network interface module is a relatively expensive component of set-top boxes. This expense would be necessary when even a single television is present in the house. However, most homes contain multiple televisions, and providing each with its own set-top box and associated network interface module is a duplication of expensive components.
Another concern for homeowners is the issue of the service providers. Limitation to one service provider for all services introduced into the home through a set-top box, such as by a telephone provider, restricts the choices of a homeowner and possibly prevents the homeowner from obtaining services at the lowest competitive price. Attempting to overcome this problem with multiple service providers using a stack of multiple set-top boxes on every television in a home is not a viable solution.